TemplateFx v2.37

I am pleased to announce the release of Template v2.37 – a scriptable dynamic templating tool that enables you to write configuration templates once and deploy multiple times – never do the same thing twice. Download links and instructions can be found on the TemplateFx page. The changes in this release are summarised below: Added initial support for IPv6 to the “ip()” function. Added support for intelligent Redo and Undo… Read More »

Tracking Downloads with Google Analytics

Google Analytics does a very good job at tracking page views out of the box, but requires a bit more technical expertise to successfully track download events. There are lots of different WordPress plugins available, but they all seem very complicated and none that seemed to track download events out of the box. With this in mind I decided to come up with a simple solution that only requires a… Read More »

The Impeding Death of Java on MacOS

It seems Apple’s long term goal is to eventually drive a wooden steak through any technology that doesn’t adhere to their vision of the future. Before they had finished putting the final nails on the coffin of Flash, they have moved onto Java and placed it firmly within their crosshairs. This hasn’t been totally unwarranted though, Oracle has had a lot of bad press recently (and Sun historically) with respect… Read More »

Self-Signed CA with CRL for Java Code Signing

I am going to start off by saying that since Java 7 Update 51, that using self-signed certificates is pretty much a waste of time for Internet deployments. With Update 51, Oracle has beefed up the security aspects of Java, which now blocks self-signed JAR files from being run via the web – even for applications which only want to run within the restricted “Sandbox”. There are a couple of… Read More »

Cisco Context-Aware Diff

How many times have you tried to run a standard diff against two configuration files, only to be presented with a load of differences without any context at all? Configuration files tend to be hierarchical and usually use indentation to denote sections. To demonstrate what I mean, lets use a simple example where I have two interfaces on a Cisco router configured as follows: interface GigabitEthernet0/0/1/0 description >> Connection to… Read More »

IP Subnet Lookup using TemplateFx

Let’s think of a scenario where you have a list of IP subnets and within a TemplateFx template you want to find out which subnet a certain IP address is within. There are numerous IP calculators out there that will tell you the first and last IP address of a subnet, but few which allow you to find a matching subnet. In this scenario we have some regional pop sites… Read More »

IP QoS Lookup Table

Every now and again I need to lookup an IP ToS or DSCP value and I spend a good couple of minutes hunting for a table that contains all the different values. In some situations the ToS field might have an ECN (Explicit Congestion Notification) flag set which will alter the ToS value but keep the DSCP value unchanged. Instead of looking everytime, I decided to put together a table… Read More »

The Long Road to IPv6

There is a transition happening, albeit slowly, from IPv4 to IPv6, that is going to have an impact, but mostly on online gaming and other peer to peer services. Ever since the introduction of the Internet as we know it today, we have been using public IPv4 addresses to talk to people and to access content online. Unfortunately we have run out of IPv4 addresses as there weren’t enough to… Read More »

Cisco IOS: IPv6 Accounting using Flexible Netflow

I am a big fan of IP Accounting as it enables me to keep long term-ish statistics on a per src/dst prefix basis. I am able to work out my weekly or monthly bandwidth usage and can see how much data each host on my network uses. I can see that I have used a total of 4.7GB in the last 5 days and the majority of that has been… Read More »

Understanding PS3 NAT Types

After spending a little time investigating online gaming on the PS3, there appears to be a lot of conflicting information with regards to what NAT is and how the PS3 classifies your NAT type. Everyone who plays online seems to spend a lot of their time (instead of actually playing games) trying to achieve a different NAT type, or thinking their NAT type is why they keep getting shot. NAT… Read More »